U.S. Pat. Nos. 5,309,838, and 5,375,518 each purport to disclose a system for keeping the printing plates of a printing press at a moderate temperature. A cooling air blower girder extends longitudinally over the printing plate surface and blows cold air onto the printing plate's surfaces in order to keep its temperature at a desired value. The blast air girder contains at least one heat exchanger and at least one blower as well as at least one air return duct, which together forms a cooling air cycle, through which the air blown onto the printing plate surface is returned to the air inlet of the heat exchanger and optionally mixed with fresh air blown by the blower once again through the heat exchanger onto the printing plate surface. The blast air girder purportedly presents an energy saving compact structural unit for keeping the printing plate surface at a moderate temperature.
U.S. Pat. No. 5,452,657 purportedly relates to a temperature control system for printing press cylinders. It contains at least one compressed air line having at least one blast air opening for blowing cold air against a cylinder which is to be cooled. At least one recirculation circuit which is separate from the cold air of the compressed air line, and by which air which has been blown by the blast air opening onto the cylinder is drawn off by a blower contained in the circulation circuit and thereafter is blown parallel to the cold air again onto the cylinder. In this way, the temperature of the cold air can be active, without prior change of temperature on the cylinder. The cold air deflected by the cylinder is returned to the cylinder for additional cooling.
U.S. Pat. No. 5,098,478 relates to water based ink compositions. The water based ink composition includes water, a pigment, a non-ionic surfactant having a solubility in water of less than about 0.5 wt % and a solubilizing agent sufficient to solubilize substantially all of the non-ionic surfactant.
U.S. Pat. No. 5,026,755 purports to disclose a water based printing ink prepared from polyamid/acrylic graft copolymers. It is prepared by reacting the polyamid with the acrylic monomer or monomers in an alcohol solution in the presence of a free radical peroxidic initiator. The graft copolymer purports to be particularly useful as the resin component of a water based printing ink.
Finally, German laid open patent application DE 41 19 348 A1 purports to disclose a method for offset printing and a printing unit for waterless offset printing. A conventional offset plate is used with a water based printing ink, containing a pigment, water, 5-50 % water soluble macromolecular binding agents, and a hygroscopic organic fluid, preferably a multivalent alcohol.